It is well known that polycarbonate resins have high impact strength below a critical thickness of between about 1/2 and 1/4 inches. Above this average thickness the impact strength of polycarbonate resins is low. Additionally, the impact strength of polycarbonate resins decreases rapidly as temperatures decrease below about -5.degree. C. and also after aging the polymers at elevated temperatures above about 100.degree. C. These characteristics consequently limit the fields of applications of these resins. Thus, unmodified polycarbonate materials are not practical for use at low or high temperatures when good impact strength is required. Therefore, it is desirable to improve both the impact strength of polycarbonate resins at low and high temperatures and their aged impact strength to thereby expand the fields of application of such resins.